I believe he can spawn from any beetle. Magelo shows him being killed in several locations. I've killed him a couple of times on the 3rd floor of the temple in Elder Kazzi's room.
Trioed today with pal/clr and sk bot. No ramp/flurry afaik. Max hit on pal with max shielding was 2498 and hit fast (without slower that is). Dropped : Jeweled Scarab Band http://lucy.allakhazam.com/item.html?id=80251 It spawned on the west tunnel near zone in. We simply just cleared the 2 shissars pathing close to zone in, waited for pathing and pulled him to zone in singled. Tank was at 17.7/4.2 hp/ac and DI fired twice tho.